Vented package



J. YATES VENTED PACKAGE Oct. 24, 1944.

Filed ed. 10, 1941 dmvlzmc; BY 2 Z ATTORNEY Patented Oct. 24, 1944 UNITED sTATEs PATENT OFFICE VENTED PACKAGE John Yates, Quincy, Mass, assignor to Pneumatic Scale Corporation, Limited, Quincy, Mass., a corporation of Massachusetts Application October 10, 1941, Serial No. 414,461 7 Claims. (01; 99452) producing the package hereinafter described and particularly defined in the claims at the end of this specification.

In the drawing illustrating the preferred embodiment of the invention, Fig. 1 is a perspective view of a package embodying thepresent invention; Fig. 2 is a developed view of a doubled over or once folded blank preferably used in producing the present container; Figs. 3 and 4 are en larged cross-sectional views taken on the lines 33 and 4 -4 respectively of Fig. 1; and Fig. 5 is a perspective view of a modified form of the present invention.

Experience has shown that in the packaging of freshly roasted coffee carbon dioxide gas is gradually liberated within the container for a substantial period of time after the coffee has been packaged. When freshly roasted coffee has been packaged in bags of material impervious to air and the bags sealed the internal-pressure within the sealed bag has oftentimes risen to the point where rupture of the bag and particularly of the sealed seams thereof has occurred. Because of the desirability of preventing the exposure of the coffee to the atmosphere a hermetically sealed container of air impervious material is required sothat the problem of preventing rupture ofthe container is one which has heretofore been the subject of much thought and study.

- At the present time various heat sealable and air impervious materials are available including the rubber-like product commercially sold as Pliofilm." In accordance with the present invention the container for producing the present package-may and preferabl will be formed of a sheet of heat sealable and air impervious material, such as a sheet of Pliofilm.

be packaged. Thereafter the top of the bag may 'be heat sealed to hermetically seal the cofiec within the container.

Preferably the sheet is folded and heat sealed along the- I in contact.

In order to provide a structure of container in which theinternal gas pressure may be controlled and' maintained below an amount sumcient to cause the bag or the heat sealed seams to burst, one of the heat sealed seams of the bag' is provided with an elongated unsealed portion communicating with the exterior and interior of the bag and forming in effect a vent. This vent is normally closed by the natural resiliency of the bag forming material which operates to maintain the surfaces forming the walls of the vent, When, however, the internal gas pressure begins to rise and reaches a point sufficient to force apart the normally contacting walls of the vent, then the gas is permitted to escape to the atmosphere, lowering the internal gas pressure to a point slightly above atmospheric pressure,.so that in the package embodying the present invention a slight differential in pres-- sure exists between the interior and exterior of the package at alltimes and this, together with the fact that the Walls of the opening comprising the vent, are naturally held in contact by the inherent resiliency of the material, serves to prevent the entrance of air through the vent into the interior of the package, so that in effect all of the advantages of a hermetically sealed package are obtained while the difiiculty which has heretofore been experienced because of the development of excessive internal gas pressure within the package is avoided in a simple, practical and inexpensive manner.

Referring now to the drawing, the container herein illustrated comprises a bag Ill preferably produced from a blank l2 of flexible sheet material impervious to air and also capable of being sealed preferably by'heat and pressure. In producing the illustrated bag, the blank is first folded once upon itself so that the folded edge l4 forms one of the closed sides of the flat bag. Then the opposite side and the bottom of the flat bag are heat sealed by the application of heat and presure to form the bottom and side seams and bottom seams produced by heat sealing, as

above described.

In order to form a vent for the package, it is preferred that during the sealing of the side seam It, as shown 2, a portion thereof be leftprovision of cut-out portions in the usual heat sealingand pressing members used to form the seam It. The portion of the seam conforming to the outline of the cut-out members will remain unsealed,'providing an elongated narrow vent communicating with the interior and also the exterior of the package. Because of the na-' tural resiliency of the bag forming material and of the fact that the vent,is elongated and relatively narrow, the walls of the vent remain in contact to be subsequently forced open when a substantial increase in internal gas pressure occurs withinthe package, and when such excess of pressure has been relieved then the walls of the prevent'the introduction of air into the package. In practice the container after having beenformed in the manner shown in Fig. 2 so as to provide a sealed seam Is at the bottom and a v sealed seam It at one side, may then be filled with the commodities such as'cofiee, and if desired prior to filling the bag may be caused to assume a shape rectangular in section in "accordance withthe usual practice and the top seam of the bag sealed in any usual or-preferred manner to hermetically seat the coffee within the container. As illustrated in Fig. 1, an elongated heat sealed I seam 30 is provided and folded down upon the g top or the container and the triangular end tabs 32, 34 may then be folded inwardly on top ofthe A top of the container, as shown in Fig. 1. The bottom seam It may be similarly folded and the sideseam I8 folded upon the side of the container; V

As a modification of the package and container shown in-Flgs. 1 and 2, the structure'illustrated in Fig. may be used wherein the vent 2| is formed in the heat sealed top seam 3|.

From the description thus far, and by reference to the drawing, it will be observed that when the coflee or other gas liberating material is packaged in the manner described and in a container embodying the vent 20, then as the gas pressure develops within the package a point is reached where the'diii'erential pressure between .the interior and exterior of the package is suflicient to force apart the normally contacting walls of the vent 20, permitting escape of a sumcient amount of the gas or air within the package to reduce the internal pressure to a point where it is slightly in excess of atmospheric pressure and where the walls of the vent 20 are again permitted to come in contact. The elongated formation of the vent 20 assists in insuring the continued maintenance all of the advantages of a hermetically sealed package are obtained while the difilculty which heretofore has been experienced because of the tendency of packages of this character to burst by reason of excessive internal gas pressure is eliminated. At the same time the structure of ing operations which may be performed upon the 'usual automatic packaging machine.

Whilethe preferred embodiments of the invention have been herein illustrated and described,

5 it will be understood that the invention may be embodied in other forms within the scope of the following claims.

' Having thus described the invention, what is claimed is:

1. A package comprising a hermetically sealed bag or air impervious resilient material containing a commodity having gas liberating characteristics, said bag being provided with an elongated narrow vent opening formed therein communicating with the interior and with the exterior of the bag for automatically maintaining the gas pressure within the bag slightly above atmospheric pressure..the-length oi. said vent being many times its width whereby to enable the inherent resiliency or the walls of the vent to close the vent until the interior gas pressure substantially exceeds the external pressure.

2. A package comprising a hermetically scale bag of air impervious resilient material contain- 5 ing a commodity having gas liberating characteristics, said bag having marginal sealed seams and an elongated narrow vent opening formed between the components of one of said seams communicating with the interiorand exterior of the bag for automatically maintaining the gas pressure withinthe bag slightly above atmospheric pressure, the length of said vent being many times its width whereby to enable the inherent resiliency of the walls of the vent to close 35 the vent until the interior gas pressure substantially exceeds the external pressure.

- 3. A package comprising a hermetically sealed bag of. air impervious resilient material containing a commodity having gas liberating characteristics, said bag having outwardly projecting marginal sealed seams and an elongated narrow vent opening formed between the components of one or said seams communicating with the interior and exterior of the bag for automatically 5 maintaining the gas pressure within the bag slightly above atmospheric pressure, the length of said vent being manytimes its width whereby to enable the inherent resiliency of the walls of the vent to close the vent until the interior gas 50 pressure substantially exceeds the external pressure.

4. A package comprising a hermetically sealed with outwardly projecting heat sealedseams and an elongated vent opening formed between the components of one of the seams, said opening communicating with the interior and exterior oi the bag and automatically maintaining the gas pressure within the bag slightly above atmospheric pressure, the length of said vent being many times-its width whereby to enable the inherent resiliency of the walls of the vent to close the vent until the interior gas pressure substantially exceeds the external pressure.

5. A package comprising a hermetically sealed bag of air impervious resilientmaterial containing a commodity having gas liberating characteristics, said bag beingprovided with a top seam and an elongated narrow vent opening formed therein, said opening communicating with the interior and'exterior of the bag for maintaining the gas pressure'within the bag slightly above atmosphericpressure, the length of said vent being many times its width whereby to enable the inherent resiliency of the 'walls of the vent to close the vent until the interior gas pressure substantially exceeds the external pressure.

6. A package comprising a hermetically sealed bag of air impervious resilient material containing a commodity havinggas liberating characteristics, said bag having outwardly projecting marginal sealed seams and an elongated narrow vent opening formed in one of asid seams'comprising an unsealed portion between the contiguous face of said one seam, said vent communicating with the interior and exterior of the bag for automatically maintaining the gas pressure within the bag slightly above atmospheric pressure, the length of said vent being many times its width whereby to enable the resiliency of the walls of the vent to close the same until the interior gas pressure substantially exceeds the external pressure.

7. A package for cofl'ee comprising a hermeti-- cally sealed bag of heat sealable, sheet rubber vent being many times its width whereby to enable the resiliency ofthe walls of the vent to close the same until the interior gas pressure substantially exceeds the external pressure.

JOHN YATES. 

